Spare GALAXY S5 as Hardware Wallet

[ClashBit]

Hi,

I am looking to create my own hardware wallet where I can store a good bunch of Bitcoins (100+ BTC) and also have the ability to transfer them fast qith QR codes. I have trezor which is something like this but I thought that it could be a good idea to do something with this spare S5 to create something secure.

How would you do this? I would need it to connect to the internet for transactions but how can I prevent being hacked since its android? Will an Iphone work better?

I know mycellium could do something like this, please be detailed on what is the best setup.

I like paper wallets but they become hard to spend sometimes if needed.

Thanks

[LiteCoinGuy]

i cant help you with that but just an adive:

splitting your funds would be more secure than putting 100BTC on your phone.

[ClashBit]

Yes, it wouldn't act as a phone since I have my phone it would be a hardware wallet which will be limited to BTC only I wouldn't install nothing more. I have my regular phone for daily use.

Thanks

[chaoman]

why not use the trezor?

[tommorisonwebdesign]

Phones aren't really great to use as hardware wallets. I would suggest using tezor, or alternatively you could send the 100 mBTC to a paper wallet for cold storage.

[Delek]

I will only recommend that only if the S5 runs a full Linux distro natively. Android is a very dynamic OS, an update in his internal .apks or the OS itself can ruin everything your wallet does (permission things, connection capabilities, etc)
Another thing to considerate is a full backup routine, maybe every week or something like that. (and I don't know if that will break the "full autonomous hardware wallet" principles)

[RedDiamond]

You should wait at least until Samsung releases patches for Stagefright bug. That should happen quite soon, please see

https://www.theverge.com/2015/8/5/9099627/google-stagefright-android-vulnerability-protect-patch
http://www.zdnet.com/article/after-stagefright-samsung-and-lg-join-google-with-monthly-android-patches/

[jaydipmodhwadia]

I would definitely agree using a paper wallet.... More secure plus much more smaller so you can easily hide it away (and forget about it xD)

[Muhammed Zakir]

If you are connecting to Internet, it may not be good to store huge amount of Bitcoins in a phone. Actually, IMHO, huge amounts of Bitcoins should be stored in cold storage even if you are a computer geek.

You must wipe your phone completely and start fresh. It's better not to install any app other than the wallet you are using.

[Kasawari]

not a good idea i think.
what if someone stole you phone?

[Muhammed Zakir]

not a good idea i think.
what if someone stole you phone?

What if someone stole your paper wallet? What if someone stole your hardware wallet(Trezor, Case, HW1 etc...)?

[gablay12]

There will be a risk.You can devide your risks but you can not decrease the total risk.It can be stolen, formatted or lost.

I do not recommend my way but I will just tell what I do.I have hired a safe (deposit box) at a local bank.I have my paper BTC wallets stored there.

Do I have a risk?Yes.If the bank is robbed or a fire takes place my investment is gone.

[tspacepilot]

So far, all of the folks saying it's not a good idea haven't really said why it would or wouldn't work.

If I were going to do this, I would:

* Install Cyanogenmod and a propery recovery
* Go ahead and remove the radio blobs so the phone has no way to connect to cell phone networks

At this point, you're sure that you have a non compromised android.  You could then use Andreas Schildbach's bitcoin wallet for andoird as it's an open-source wallet you can check for issues.

Finally, it goes without saying that you'd want to make a backup of the entire device (but especially the private keys).

Okay, so, if this is not a good idea, lets hear why, not just "not a good idea".

[unholycactus]

I think it would be smarter to split your funds between paper wallets and your Trezor device. I guess nothing keeps you from keeping a small amount on your S5 though.

[tspacepilot]

I think it would be smarter to split your funds between paper wallets and your Trezor device. I guess nothing keeps you from keeping a small amount on your S5 though.

Surely nothing keeps him from keeping any amount on an S5.  But I thought that this thread would be about the technical details of the effort (this is the technical discussion board).  Seems like 90% of the posters in this thread just can't help saying "I don't like your idea".  But come'on, people, surely someone has a technical opinion if you want to hang out in this board.